Serum 25-hydroxyvitamin D 25(OH)D, and dietary and supplemental vitamin D may influence cognitive outcomes. Section investigators examined the associations of sex, age, race, and vitamin D status and intake with longitudinal change in various cognitive domains in a sample of ethnically and socioeconomically diverse US urban adults. Participants were drawn from Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. and were followed for an average of 4.64. Investigators found a consistent relationship between vitamin D status (overall) and supplemental intake (older women and black adults), with a slower rate of decline in the domain of verbal fluency. Higher dietary intake of vitamin D was linked to slower rate of decline in verbal memory among younger women, and a slower rate of decline in visual memory/visuoconstructive abilities among white adults. All other associations were inconsistent. These results show that vitamin D status and intakes were inversely related to domain-specific cognitive decline in US urban adults. Systemic inflammation can affect cognitive performance over time. Section investigators examined associations between systemic inflammation and cognitive performance among African Americans and Whites urban adults, stratifying by sex, and age group and by race in data from Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. C-reactive protein (CRP) was linked to poorer baseline mental status among younger women and poorer attention in older women and African-Americans. ESR was related to faster decline on verbal memory among older men; with poorer performance on attention tests overall and among African-Americans; on verbal fluency among older women and on executive function overall, in older men, and in African Americans. Albumin was linked to slower attention decline among older men, over-time improvement in executive function overall, and better baseline psychomotor speed among African-Americans. These results suggest strong associations between systemic inflammation and longitudinal cognitive performance largely among older individuals (>50y) and African-Americans. Chronic systemic inflammation is also positively associated with structural and functional brain changes representing early markers of Alzheimer's Disease (AD) and cognitive decline. Section investigators examined associations between systemic inflammation and cognitive performance among African Americans and Whites urban adults in participants Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Cytokines known to be positively linked to AD incidence among others were tested against cross-sectional and longitudinal cognitive function, stratifying at 50 years by age, sex and race. IL1beta was positively associated with a faster rate of executive function decline among older adults and, in the total population, IL-6 was linked to a faster decline on a test of verbal memory Among younger participants, IL-18 was linked to a poorer performance on a test of attention at baseline though a slower rate of decline with higher IL-18 was detected for a test of psychomotor speed in older adults. Among Whites, unlike among African-Americans, IL-6 was associated with a better baseline performance on two tests of verbal and working memory. In this study, cytokines were shown to be associated with age-related cognitive decline among middle-aged and older urban adults in an age group and race-specific manner. Section investigators examined the relation between socioeconomic status (SES) and white matter integrity of the brain's primary cortical regions, and evaluated potential moderating influences of age and self-identified race. Participants were 192 socioeconomically diverse African American and white participants from Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging. Diffusion tensor imaging was used to estimate regional fractional anisotropy (FA) to quantify the brain's white matter integrity and trace to capture diffusivity. There were no significant interactions of SES, age, and race for any region. Individuals with low SES had lower FA in all regions, and higher trace in the right and left frontal, right and left temporal, and left occipital lobes. Findings remained largely unchanged after inclusion of sensitivity variables. Older age was associated with lower FA and greater trace for all regions, except for the right temporal lobe with FA. No main effects were found for race in FA, and Whites had higher trace values in the parietal lobes. Novel findings of this study indicate that relative to the high SES group, low SES was associated with poorer white matter integrity and greater diffusivity. These results may, in part, reflect exposures to various biopsychosocial risk factors experienced by those of lower SES across the lifespan, and may help explain the preponderance of cognitive and functional disparities between socioeconomic groups. This study sought to examine the interactive relations of SES and race to corticolimbic regions that may play a key role in translating stress to the poor health outcomes overrepresented among those of lower socioeconomic status and African American race. Participants were 200 participants in HANDLS SCAN. Brain volumes were derived using T1-weighted MP-RAGE images. There were SES by race interactions for right medial prefrontal cortex, left medial prefrontal cortex, left orbital prefrontal cortex, and left anterior cingulate cortex, wherein higher SES Whites had greater volumes than all other groups. Additionally, higher versus lower socioeconomic status persons had greater right and left hippocampal and amygdalar volumes. Whites had greater right and left hippocampal, right orbital prefrontal cortex, and right anterior cingulate cortex volumes than African Americans. Among many factors, the higher levels of lifetime chronic stress associated with lower SES and African American race may adversely affect corticolimbic circuitry. These relations may help explain race- and socioeconomic status-related disparities in adverse health outcomes. Lower socioeconomic status (SES) is related to poorer cognitive performance, but the neural underpinnings of this relation are not fully understood. Section investigators examined whether SES-linked decrements in executive function were mediated by smaller dorsolateral prefrontal cortex (DLPFC) volumes in 190 participants from HANDLS SCAN. Regional brain volumes were derived using T1-weighted MP-RAGE images. Moderated mediation demonstrated that DLPFC volume significantly mediated the association between SES and Trails B in Whites, but not in AAs. No mediations were found for Digit Span Backwards or verbal fluency, although SES was related to all tests. The DLPFC may be important in the association of SES and mental flexibility for White, but not AA adults. It is possible that the well-replicated advantages of high SES among Whites do not readily translate, on average, to AAs. These findings highlight the importance of brain volume for cognitive functioning, while adding to the literature on sociodemographic health disparities.